LMK00301: Minimum pulse width

Danilo A.

Part Number: LMK00301

Hi Team,

Our customer is using the LMK00301SQE/NOPB and need to pass a synchronisation pulse in the buffer. He would like to know the minimum pulse width he needs and the amount of jitter he can expect (the slew rate is around 2V/ns).

Regards,

Danilo

over 1 year ago

0 Kia Rahbar over 1 year ago

TI__Expert 8585 points

Hello Danilo,

The input must have a 40% to 60% duty cycle.

Figures 12 -14 in the data sheet show the jitter with respect to slew rate for different frequencies.

Regards,

Kia Rahbar

0 Danilo A. over 1 year ago in reply to Kia Rahbar

TI__Mastermind 24715 points

Hi Kia,

Thank you for your response. According to our customer,

I am confused by this answer. Since the buffer is able to handle data, as well as DC signals (shown in the following images), I assumed it could handle non periodical signals with varying duty cycles, such as a pulse.

If this is not the case and only clock signals with the mentioned duty cycle can be used, your datasheet is quite misleading.

Regards,

Danilo

0 Kia Rahbar over 1 year ago in reply to Danilo A.

TI__Expert 8585 points

Hello Danilo,

Apologies, I have misspoken.

The LMK00301 can support a non periodic signal.

Regards,

Kia Rahbar

0 Danilo A. over 1 year ago in reply to Kia Rahbar

TI__Mastermind 24715 points

Hi Kia,

Our customer has a follow up inquiry below.

This is what I though. Therefore, is there a limit to the width of the pulse the fbuffer will accept? And what would be the approximate additive jitter on this pulse?

Regards,

Danilo

0 Kia Rahbar over 1 year ago in reply to Danilo A.

TI__Expert 8585 points

Hello Danilo,

There is no limit to the pulse width. The additive jitter will be as shown in the Electrical Characteristics section of the data sheet.

Regards,

Kia Rahbar

0 Danilo A. over 1 year ago in reply to Kia Rahbar

TI__Mastermind 24715 points

Hi Kia,

Here is another follow up inquiry from our customer.

I would also like to know if the crystal input (OSCin) would be able to support the sync pulse as well (since the information about this input is limited)

Regards,

Danilo

0 Kia Rahbar over 1 year ago in reply to Danilo A.

TI__Expert 8585 points

Hello Danilo,

I checked with our design team and the OSCin will be able to support a non periodic signal as well.

Also, the minimum pulse width is 1/2 the period of the largest frequency the buffer can support (0.5 * 1/3.1 GHz = 166 ps).

Please update the customer regarding the minimum pulse width.

Regards,

Kia Rahbar

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LMK00301: Minimum pulse width